Assessing Legacy Effects of Wildfires on the Crown Structure of Fire-Tolerant Eucalypt Trees Using Airborne LiDAR Data
Round 1
Reviewer 1 Report
I had previously reviewed a version of this manuscript for an ecology-focused journal. In that review I made several minor comments, overall liked the paper, but thought it was better suited for a remote sensing-focused journal.
In my opinion, I believe that this manuscript is suitable for Remote Sensing with minor edits (see below).
The authors develop a novel method, and for that I listed the originality as high. The usefulness of this method only be assessed by applying it to a large area and learning what ecological knowledge and interpretation can or can't be produced.
The authors did a good job of incorporating my previous comments with a couple of exceptions, which are re-listed below. I did not attempt to assess whether the authors incorporated any other previous reviewers' comments. However, I don't remember the supplementary material (but it may have been there), so this could have been added at a reviewer's suggestion.
Minor comments:
Line 388: I still believe that this sentence is difficult to parse and suggest rewriting it.
Figure 5: Why doesn’t the bottom right panel show statistically distinct classes? I presume that they were not statistically distinct based on the figure, but that should be shown in the panel. (Missed this in the previous version.)
Figure 8 caption: Readers, with careful reading, can deduce that the triangles and circles represent minimum and maximum values for individual trees. Could the authors just state this in plain text?
Author Response
Line 388: I still believe that this sentence is difficult to parse and suggest rewriting it.
Response 1: We have rewritten this sentence for better understanding please see line 387 to 388.
Revised sentence: "In terms of tree size, mean diameters (DBHOB) of the largest trees (>50 cm DBHOB) were not significantly different among fire- severity classes; however, mean DBHOB of the smaller mature trees (DBHOB 20 to 50 cm) was significantly lower at moderate- than high-severity sites (Figure 5)."
Original sentence: DBHOB means by diameter class of field-measured trees were similar among the fire-severity classes, with the exception of significantly smaller tree diameters at moderate- than high-severity sites in the 20 - 50 cm DBHOB class (Figure 5).
Figure 5: Why doesn’t the bottom right panel show statistically distinct classes? I presume that they were not statistically distinct based on the figure, but that should be shown in the panel. (Missed this in the previous version.)
Response 2: We have now inserted the letters in bottom right panel as per suggestion to more clearly show that mean DBHOB of the largest trees did not significantly differ among fire-severity classes.
Figure 8 caption: Readers, with careful reading, can deduce that the triangles and circles represent minimum and maximum values for individual trees. Could the authors just state this in plain text?
Response 3: We have made two changes to the figure 8 caption:
Added “of individual trees” to the first sentence Added “values for individual trees; other" in the third sentence
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The paper is interesting and it provides a reasonable contribution to the body of knowdlege. Nevertheless, it may be improved further: 1-Introduction-The problem is well described, as well as the objectives of the research. Consider adding more relevant references at international level. 2-Justify in a better way, why only 17 sites for the sampling plots of the study. The sampling and data collection process is well described and seems consistent. 3-The methodology is well described as well as the results. 4-You may improve the conclusion, as it seems quite small and it doesn’t valorise your work.Author Response
1-Introduction-The problem is well described, as well as the objectives of the research. Consider adding more relevant references at international level.
Response 1: Thanks, and well appreciated. We have added a few new international references as follows:
Line 40 to 41: Wildfire impacts on forest ecosystems worldwide are predicted to change under fire and climate regimes [1-4], reference 4 a new addition (Lindner., et al. Climate change impacts, adaptive capacity, and vulnerability of European forest ecosystems. Forest Ecology and Management 2010, 259, 698-709.
Line 50 to 52: Crown damage and loss associated with high-severity fires will impact on tree carbon uptake, influencing stand productivity at least until the functional leaf area is recovered [11,12], reference no 12 a new addition (Lang, A.C.; Hardtle, W.; Bruelheide, H.; Krober, W.; Schroter, M.; von Wehrden, H.; von Oheimb, G. Horizontal, but not vertical canopy structure is related to stand functional diversity in a subtropical slope forest. Ecological Research 2012, 27, 181-189, doi:10.1007/s11284-011-0887-3.)
Line 57 to 58: Fire impacts on tree crowns will likely vary depending on the pre-fire architecture [15], reference no 15 a new addition (Banin, L.; Feldpausch, T.R.; Phillips, O.L.; Baker, T.R.; Lloyd, J.; Affum-Baffoe, K.; Arets, E.; Berry, N.J.; Bradford, M.; Brienen, R.J.W., et al. What controls tropical forest architecture? Testing environmental, structural and floristic drivers. Global Ecology and Biogeography 2012, 21, 1179-1190, doi:10.1111/j.1466-8238.2012.00778.x.)
Line 64 to 65: the contribution of eucalypt crowns versus understorey to these spectral data and [18], reference no 18 a new addition (Latifi, H.; Heurich, M.; Hartig, F.; Muller, J.; Krzystek, P.; Jehl, H.; Dech, S. Estimating over- and understorey canopy density of temperate mixed stands by airborne LiDAR data. Forestry 2016, 89, 69-81, doi:10.1093/forestry/cpv032)
Line 94 to 95 This has implications for understanding post-fire recovery of forest productivity [50], reference no 50 a new addition (Hicke, J.A.; Asner, G.P.; Kasischke, E.S.; French, N.H.F.; Randerson, J.T.; Collatz, G.J.; Stocks, B.J.; Tucker, C.J.; Los, S.O.; Field, C.B. Postfire response of North American boreal forest net primary productivity analyzed with satellite observations. Global Change Biol. 2003, 9, 1145-1157, doi:10.1046/j.1365-2486.2003.00658.x.)
2-Justify in a better way, why only 17 sites for the sampling plots of the study. The sampling and data collection process is well described and seems consistent.
Response 2: We have more clearly indicated why our study was restricted to 17 sites, as follows (Line 145 to 148):
Revised text: "Our study design involved clusters of plots at each of 17 sites to improve sampling efficiencies in the logistically challenging (steep and isolated) terrain. These 17 sites represented the most accessible combinations of the overlap of the wildfire complex with our selected forest type and the lidar-data extent. They …"
Original text: We assessed trees at 17 field sites, which were four replicates each of four wildfire severity types …
3-The methodology is well described as well as the results.
Response 3: Thanks.
4-You may improve the conclusion, as it seems quite small and it doesn’t valorise your work.
Response 4: We have further highlighted the importance of our paper in the Conclusion by adding the following text (Line 658 to 661):
"The implications of these legacy effects on, for example, tree productivity and the accuracy of biomass allometric equations warrants further study. Trees are keystone forest structures so improved assessment of changes in tree structure improves understanding of forest landscape processes. Our unique tree-based lidar crown metrics demonstrate" the utility of airborne lidar data for assessing post-fire severity effects on structurally complex tree crowns.
Author Response File: Author Response.pdf
Reviewer 3 Report
The manuscript presented an interesting and valuable study to better understand the fire ecology in a fire-prone area. The method design is a good combination of field experiments and the use of remote sensing data. Overall, the manuscript has a good quality of writing and organization. I recommend this manuscript to be accepted.
A suggestion for improvement of Figure 1 is to use a greyscale map or a simpler map showing the necessary administrative boundary of the study area. The current basemap used in the Figure 1 is too noisy and contains too much unnecessary details, which will harm the audience from distinguishing the more important information from the figure.
Author Response
A suggestion for improvement of Figure 1 is to use a greyscale map or a simpler map showing the necessary administrative boundary of the study area. The current base map used in the Figure 1 is too noisy and contains too much unnecessary details, which will harm the audience from distinguishing the more important information from the figure.
Response 1: We have modified the Figure 1 as per suggestion and replaced it. The noisy base map was replaced with grey base map indicating few major places of the Victoria state surrounding the study area. The administrative boundary is shown in the background.
Author Response File: Author Response.pdf
